<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>vue</title>
    <script type="text/javascript" src="../../js/vue.js"></script>

</head>
<body>
    <div id="root">
        姓：<input type="text" v-model="firstName"> </br>
        名：<input type="text" v-model="lastName"> </br>
        全名：<span>{{fullName}}</span>
    </div>

    <script type="text/javascript">
        Vue.config.performance = false;
        const vm = new Vue({
            el:'#root',
            data() {
                return {
                  firstName:'张',
                  lastName:'三'
                };
            },
            // 计算属性--多次读取会缓存
           
            computed:{
                /* fullName:{
                     // 初次读取被调用 或者所依赖的数据发生变化
                    get(){
                        console.log('call get')
                        console.log(this)
                        return this.firstName + '-' + this.lastName
                    },
                    set(value){
                        const arr = value.split('-')
                        this.firstName = arr[0]
                        this.lastName = arr[1]
                    }
                } */
                // 简写--确定不会使用set
                fullName(){
                    console.log('call set')
                    return this.firstName + '-' + this.lastName
                }
            }
        })

    </script>

</body>
</html>